Presidential campaigning in the United States continues even with Hurricane Milton hitting Florida.

Vice President Kamala Harris visited Nevada and Arizona on Thursday, while former President Donald Trump discussed economic issues in the auto industry capital of Detroit in Michigan.

Both the Harris and Trump campaigns are using their travel strategically, trying to increase support with key voting blocs who could decide an election expected to be exceedingly close.

Trump has emphasised picking up votes in heavily Hispanic parts of Pennsylvania, including Reading, where he held a rally on Wednesday.

Also wooing blue-collar voters in the former coal mining town and President Joe Biden’s childhood hometown of Scranton, Trump vowed to "drill, baby, drill" for oil and assailed Harris on the economy.

Harris was out west to yet another swing state, Nevada, as her campaign looked to increase support among Hispanic voters there, especially men.

But the White House said she would be kept informed throughout the day about Hurricane Milton.

The monster hurricane crashed into Florida late on Wednesday with Biden warning that it could be the "storm of the century."

Meanwhile, former President Barack Obama also hit the campaign trail on Thursday night, making his first appearance for Harris at a rally in Pittsburgh, a day after Republican rival Donald Trump charged through the must-win state.

Harris campaign said Obama's trip to Pennsylvania is the first stop in what will be a month of campaigning for the vice president in the seven swing states where the 2024 election is likely to be decided. (AP/AFP)